JavaScript+canvas实现七色板效果实例

本文实例讲述了JavaScript+canvas实现七色板效果。分享给大家供大家参考，具体如下：

效果图如下：

html：

<canvas id="canvas" class="canvas" width="600" height="600"></canvas>

css：

html,body{margin: 0;padding: 0}
.canvas{display: block; margin-left:auto;margin-right:auto;margin-top: 50px;}

javascript：

var disk = [
    {
      area:[{x:0,y:0},{x:600,y:0},{x:300,y:300}],
      color:"#CBF263"
    },
    {
      area:[{x:0,y:0},{x:0,y:600},{x:300,y:300}],
      color:"#5CB6D0"
    },
    {
      area:[{x:0,y:600},{x:300,y:600},{x:150,y:450}],
      color:"#FE9CCD"
    },
    {
      area:[{x:150,y:450},{x:300,y:300},{x:450,y:450},{x:300,y:600}],
      color:"#A696C3"
    },
    {
      area:[{x:300,y:600},{x:600,y:600},{x:600,y:300}],
      color:"#FBC421"
    },
    {
      area:[{x:600,y:300},{x:600,y:0},{x:450,y:150},{x:450,y:450}],
      color:"#FF5061"
    },
    {
      area:[{x:450,y:450},{x:450,y:150},{x:300,y:300}],
      color:"#FDEA11"
    }
]
window.onload = function(){
    var canvasDom = document.getElementById("canvas");
    var ctx = canvasDom.getContext("2d");
    drawDisk(disk,ctx)
}
function drawDisk(disk,ctx){
    for(var i = 0;i<disk.length;i++){
      ctx.beginPath();
      ctx.moveTo(disk[i].area[0].x,disk[i].area[0].y);
      for(var j = 1;j<disk[i]["area"].length;j++){
        ctx.lineTo(disk[i].area[j].x,disk[i].area[j].y);
      }
      ctx.closePath();
      ctx.fillStyle = disk[i]["color"];
      ctx.fill();
    }
}

希望本文所述对大家JavaScript程序设计有所帮助。